It's simple. Most of these guys don't care if they live or die, they are CRAZY! Someone shooting them back isn't something that's going to stop them because they usually kill themselves anyway. And if multiple guys are packing and "good guy 1" kills the "bad guy" when "good guy 2, 3, ad 4" pull out their firearms, they are going to think good guy 1 is the bad guy. I don't agree necessarily with "gun free zones" but there has to be a better solution by hiring well trained people to handle these situations.